Over the recent years, as a device has been speeded up and has attained a higher frequency, an improvement of a heat radiation property and a stable supply of a power voltage have been requested of a semiconductor package. A conventional package takes a structure of sealing the package by a heat radiation plate exhibiting a high thermal conductivity and connecting a semiconductor element by use of a thermal conductive material, thereby enhancing the heat radiation property. Further, the conventional package takes a structure of disposing a multiplicity of chip capacitors on the substrate in order to realize the stable supply of the power voltage.
The improvements of these properties require disposing multiple passive components and multiple members on the substrate and require, in another aspect, downsizing and thinning the package. Moreover, a reduction in radiation of electromagnetic noises and prevention of a malfunction due to the electromagnetic noises coming from outside are required corresponding to a much higher frequency.
It is generally known that the periphery of the semiconductor element is shielded by electrically connecting the heat radiation plate to the substrate. In a limited area on the substrate, however, it is difficult to provide afresh an area for establishing the connections via the conductive materials etc on the substrate and perform wiring within the substrate, and an extra cost for materials such as conductive materials and connection materials is taken.